# Explain how peristalsis moves food along the alimentary canal.

> Pearson Edexcel International GCSE Biology (4BI1) — 2.6 Nutrition: humans · Explain · 4 marks

> Food must travel from the mouth to the anus through the alimentary canal. This journey relies on muscular movements of the digestive tract rather than gravity alone.

## Mark scheme (4 marks)

1. Peristalsis involves the contraction of muscles (in the wall of the alimentary canal / oesophagus / gut)
2. The contractions squeeze / narrow the lumen behind the bolus of food
3. Muscles relax ahead of the bolus (widening the lumen in front)
4. This wave of contraction and relaxation pushes the bolus of food along / towards the anus

## Key terms

- [peristalsis](https://www.gradenine.co.uk/glossary/peristalsis)
- [alimentary canal](https://www.gradenine.co.uk/glossary/alimentary-canal)

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-peristalsis-moves-food-along-83d03483) · Published by Druglandscape Ltd.